1. Field of the Invention
The present invention relates to a recording apparatus which includes a recording head to which an ink is supplied from a detachable ink cartridge, and a maintenance method for the recording apparatus.
2. Description of the Related Art
In a recording apparatus described in Japanese Patent Application Laid-open No. 2005-178240 (FIG. 1 and FIG. 3), an ink-jet recording head is mounted on a carriage, and the recording is carried out by jetting an ink onto a recording medium, while moving with respect to the recording medium. The ink is supplied from an ink cartridge which is stationary in a main body of the recording apparatus to the recording head which moves, via an ink supply tube which is flexible.
In many cases, a tube made of a resin material is used for imparting flexibility to the ink supply tube, and a shielding property with respect to air is not perfect. Therefore, a phenomenon in which air enters into the ink by a small amount arises. This air becomes an air bubble and blocks a channel inside the recording head, thereby causing a jetting defect.
Consequently, in the recording apparatus described in Japanese Patent Application Laid-open No. 2005-178240, the ink is not supplied directly to the recording head from the ink supply tube, but the ink passed through the ink supply tube is supplied to the recording head after storing once in an ink storage section (corresponds to a damper unit 13 in Japanese Patent Application Laid-open No. 2005-178240). Moreover, air is trapped in the ink storage section, and the trapped air is discharged at a predetermined time interval by operating an air discharge valve mechanism which is attached to the ink storage section.
On the other hand, the ink cartridge, as it has been described in Japanese Patent Application Laid-open No. 2006-44236, is detachably mounted together with a case, on an accommodating section (corresponds to an ink storage section 15 in Japanese Patent Application Laid-open No. 2006-44236) of the recording apparatus. An ink receiving section in the form of a thin hollow shaft communicating with the ink supply tube is protruded, from the accommodating section. Moreover, the ink cartridge is mounted on the accommodating section by inserting the ink receiving section into an ink outflow hole of the ink cartridge. The ink infused into the ink receiving section from the ink cartridge is supplied to the recording head via the ink supply tube.
In a case of a replaceable ink cartridge, it is not possible to perfectly avoid air from entering into the ink to some extent through an engagement portion of the ink receiving section described above and the ink outflow hole, at the time of attaching or detaching the ink cartridge. The air mixed in the ink from a detachable portion of the ink cartridge, or from a tube wall of the ink supply tube is stored in the ink storage section, and can be discharged periodically by the air discharge operation as described in Japanese Patent Application Laid-open No. 2005-178240.
However, in a case of a heavy user, a substantial amount of ink might be consumed, and the ink cartridge might be replaced very frequently. Further, the ink cartridge might be attached and detached repeatedly for checking the recording apparatus. In such a case, a substantial amount of air beyond expectation is accumulated in the ink storage section, and the discharge of the air by the periodic discharge operation is not sufficient, which causes a jetting defect of the recording head.